Classes in ES6
Deepak Grover, Hanu Prateek Kunduru · Apress eBooks · 2017
Prior to ES6, classes never existed in JavaScript, but from the early days, many patterns have existed to emulate classical class-oriented development. The concept of classes was teased in various different forms, primarily due to the fact that classes and classical inheritance could not be supported inside JavaScript in a clean straightforward way. A class in ES6 is simply a function under the hood. It is nothing more than syntactical sugar over Objects and Prototypes, offering a convenient declarative form for class patterns that encourage interoperability.